leisure vs tranquillity

leisure

noun
  • Time at one's command, free from engagement; convenient opportunity; hence, convenience; ease. 

  • Free time, time free from work or duties. 

  • Freedom provided by the cessation of activities. 

tranquillity

noun
  • The state of being tranquil; peacefulness, the absence of disturbance or stress; serenity; calm. 

How often have the words leisure and tranquillity occurred in a corpus of books? (source: Google Ngram Viewer )